What were Lincoln beliefs about the separation of the Union

He gave several reasons, among them his belief that secession was unlawful, the fact that states were physically unable to separate, his fears that secession would cause the weakened government to descend into anarchy, and his steadfast conviction that all Americans should be friends towards one another, rather than enemies. But it may have been the last point that he considered the most important to his argument: Secession would destroy the only democracy in existence and prove for all time - to both future Americans and the world - that a government of the people could not survive.

no statements but ok.

the statement that best describes the idea of manifest destiny that was used in the 19th century would be that "it was fate that the united states would continue to  expand westward," since people thought the us was "destined" to do so.